Comparison of Bioelectrical Impedance Analysis, Slaughter Skinfold-Thickness Equations, and Dual-Energy X-ray Absorptiometry for Estimating Body Fat Percentage in Colombian Children and Adolescents with Excess of Adiposity

Abstract

Dual-energy X-ray absorptiometry (DXA) has been considered a reference method for measuring body fat percentage (BF%) in children and adolescents with an excess of adiposity. However, given that the DXA technique is impractical for routine field use, there is a need to investigate other methods that can accurately determine BF%. We studied the accuracy of bioelectrical impedance analysis (BIA) technology, including foot-to-foot and hand-to-foot impedance, and Slaughter skinfold-thickness equations in the measurement of BF%, compared with DXA, in a population of Latin American children and adolescents with an excess of adiposity. A total of 127 children and adolescents (11⁻17 years of age; 70% girls) from the HEPAFIT (Exercise Training and Hepatic Metabolism in Overweight/Obese Adolescent) study were included in the present work. BF% was measured on the same day using two BIA analysers (Seca^® 206, Allers Hamburg, Germany and Model Tanita^® BC-418^®, TANITA Corporation, Sportlife Tokyo, Japan), skinfold measurements (Slaughter equation), and DXA (Hologic Horizon DXA System^®, Quirugil, Bogotá, Columbia). Agreement between measurements was analysed using <i>t</i>-tests, Bland⁻Altman plots, and Lin's concordance correlation coefficient (<i>ρ</i>c). There was a significant correlation between DXA and the other BF% measurement methods (<i>r</i> > 0.430). According to paired <i>t</i>-tests, in both sexes, BF% assessed by BIA analysers or Slaughter equations differ from BF% assessed by DXA (<i>p</i> < 0.001). The lower and upper limits of the differences compared with DXA were 6.3⁻22.9, 2.2⁻2.8, and -3.2⁻21.3 (95% CI) in boys and 2.3⁻14.8, 2.4⁻20.1, and 3.9⁻18.3 (95% CI) in girls for Seca^® mBCA, Tanita^® BC 420MA, and Slaughter equations, respectively. Concordance was poor between DXA and the other methods of measuring BF% (<i>ρ</i>c < 0.5). BIA analysers and Slaughter equations underestimated BF% measurements compared to DXA, so they are not interchangeable methods for assessing BF% in Latin American children and adolescents with excess of adiposity.